Arm templates copy loop conditionally check index - azure

Question

Is there option copy iteration check conditionally in ARM templates? Example if copy index is zero set another value?
My ARM Code:
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"location": {
"type": "string",
"defaultValue": "[resourceGroup().location]"
},
"storageAccountName": {
"type": "string"
},
"mediaServicesAccountName": {
"type": "string"
}
},
"functions": [],
"resources": [
{
"type": "Microsoft.Storage/storageAccounts",
"apiVersion": "2021-01-01",
"name": "[concat('storage', copyIndex(), uniqueString(resourceGroup().id))]",
"location": "[parameters('location')]",
"sku": {
"name": "Standard_LRS"
},
"kind": "StorageV2",
"copy": {
"name": "storagecopy",
"count": 3
}
},
{
"type": "Microsoft.Media/mediaservices",
"apiVersion": "2020-05-01",
"name": "[parameters('mediaServicesAccountName')]",
"location": "[parameters('location')]",
"properties": {
"storageAccounts": [
{
"type": "Primary", # Primary if copyIndex is zero otherwise Secondary
"id": "[resourceId('Microsoft.Storage/storageAccounts', concat('storage', copyIndex(), uniqueString(resourceGroup().id)))]"
}
]
},
"identity": {
"type": "SystemAssigned"
},
"dependsOn": ["storagecopy"]
}
],
"metadata": {
"_generator": {
"name": "bicep",
"version": "0.3.126.58533",
"templateHash": "2006367938138350540"
}
}
}
In above code I am creating 3 storage accounts and after that I am creating azure media service, I need to map storage accounts to azure media service dynamically. Under properties, I need to use copy loop and set Primary if index is zero else Secondary for defined number of storages.
Below Block implementation is required for copy loop condition:
"storageAccounts": [
{
"type": "Primary", # Primary if copyIndex is zero otherwise Secondary
"id": "[resourceId('Microsoft.Storage/storageAccounts', concat('storage', copyIndex(), uniqueString(resourceGroup().id)))]"
}
]

Answer 1

You need to make a separate loop over storageAccounts property:
{
"type": "Microsoft.Media/mediaservices",
"apiVersion": "2020-05-01",
...
"properties": {
"copy": [
{
"name": "storageAccounts",
"count": "3",
"input": {
"type": "[if(equals(copyIndex('storageAccounts'), 0), 'Primary', 'Secondary']", # Primary if copyIndex is zero otherwise Secondary
"id": "[resourceId('Microsoft.Storage/storageAccounts', concat('storage', copyIndex('storageAccounts'), uniqueString(resourceGroup().id)))]"
}
}
]
}
}
See more information here: Property iteration in ARM templates